Organophosphato-stannanes

ABSTRACT

ORGANOPHOSPHATOSTANNANES AND CURABLE ORGANOPOLYSILOXANES CONTAINING ORGANOPHOSPHATOSTANNANE CATALYSTS.

US. Cl. 260-429.7

United States Patent ABSTRACT' OF- THE DISCLOSURE 'Organophosphatostannanes 'and curable organopolysiloxane's containing organophosphatostannane catalysts.

This is a division [of applicationSer. No. 708,501, filed Feb, 27, 1968 now;U.S,P. No. 3,527,778.

This invention relates to lorganophosphatostannanes, particularly to curable organop'olysiloxanes containing organophos'phatostannanes and more particularly to organopolysiloxane compositions having variable curing times.

'Heretofore, organotin catalysts, such as dibutyltin butoxychloride, dibutyltin' dilaurate, and the like, have been used toaccelerate the curing of organopolysiloxanes. However, it was foundthat these catalysts do not provide a satisfactory rate of cure for some applications. In addition, itwas found that in some commercial applications, it is desirable to' have a rapid cure rate, while in other commercial applicationissit'is desirable to have a slow cure rate. Obviously, there has been a need in the prior art for curable organopolysilonane compositions having variable curing! times, depending upon the commercial application. I

' It is therefore an object of this invention to prepare organophosphatostannanes, Another object of this inventionis to provide an improved curing catalyst for silicone elaston'iers; Still another'object oflthis invention is to provide organopolysiloxane compositions having variable curing times A further object'of invention is to provide organopolysiloxane"compositions which are curable in ambient moisture. A still further object of this invem tion is to provide a catalyst which may be incorporated in one and two-component systems to provide variable curingtimes. I

The foregoing objects'a'nd others which will become apparent from the following description are accomplished in accordancewith this invention, generally speaking, by incorporating'in' a curable organopolysiloxane composition a catalyst represented by tlie'tormula: I

R4-m-i1Sn[Oi (O R021 in which Y represents halogen; OR", or

R andR are organic g'roupsg -R isan alkyl or aryl group; m is an integeno ffrom 0'to 2i n'is 'aninteger greater than 0; and the sumofm and n is less than 4.

ice

methyl, propyl, butyl, hexyl, octyl, decyl; aryl radicals, such as phenyl, diphenyl, naphthyl; haloalky'l radicals, such as chlonomethyl, dichloromethyl, chloroethyl, 1- chloropropyl, l-chlorobutyl, and the like. R may also represent alkyl radicals having from 1 to 10 carbon atoms, such as ethyl, butyl, hexyl, octyl, decylfor aryl radicals, such as phenyl, diphenyl, naphthyl, and the like.

Examples of compounds embraced by the above rformula are dibutylbis diethylphosphato) stannane, dimethylbis( dimethylphosphato)stannane, dihexylbis (dipropylphosph ato) stannane, dioctylbis (ethylmethylphosphato') st atmane, didode cylbis dibutylphosphato stannane, ditetradecylbis (dihexylphosphato) stannane, dioctadecylbis (diethylphosphato stannane, butylmethoxybis dimethylphosphato stannane, methylethoxybis (diethylphosphato) stannane, hexyl prop oxybis (dipropylphosph ato stannane, octylbutoxybis methylethylphosphato) stannane, tridecyloctoxybis methylbutylphos'phato) stannane, methyldimethoxydimethylphosphatostannane, methyldiethoxydiethylpho sphatostannane, ethyldibutoxydiethylphosphatostannane,

propyldihexoxydipropylphosphatostannane,

diphenylbis diethylphosphato) stannane,

In the above formula, R may represent alkyl radicals having from 1 to '18carbon atoms, such as methyl, ethyl,

propyl, butyl, he 'g'yl, octyLiiecyl, dodecyl, tetradecyl, and o'ctadecyl; aryl radicals, such as phenyl, diphenyl, naphthyl, and the like; alkaryl radicals, such as'tolyl, xylyl, ethylphenyl, and the like; aralkyl 'ra'dicals', such as benzyl, phenethyLand the like; haloarylradicals, such as chlorophenyl, tetrachlorophenyl', dilfluorophenyl; alk enyl radicals, such as vinyl, allyl, and the-like. R may represent alkyl radicals having from 1 to "10 carbon atoms, such as cumylmethoxybis diethylphosphato) stannane, myristylbutoxybis (dibutylphosphato) stannane, styrylmethoxybis diethylphosphato stannane, vinyltris( diethylphosphato) stannane, vinylmethoxybis (dimethylphosphato) stannane, allylethoxybis dipropylphosphato stannane,

' 1-propenylethoxybis(diethylphosphato)stannane,

Z-butenylmethoxybis dibutylphosphato) stannane, 7 1,3 -butadienylmethylbis dimethylphosphato stannane,

2-pentenylmethoxybis (dihexylphosphato stannane,

vinyltris( dimethylphosphato) stannane, allyltris diethylphosphato) stannane, butyltris(dihexylphosphato)stannane,

octyltn's (dipropylphosphato) stannane, phenethyltris (dimethylpho sphato) stannane, chloromethyltris( diethylphosphato) stannane, butylbis (diethylphosphato) chlorostatmane, octylibis( dipropylphosphato) chloro stannane, phenylbis dimethylphosphato chlorostannane, butylbis=( diethylphosphato) fluorostannane, cumylbis (diethylphosphato) chlorostannane, and the like.

The stannanes may be prepared by reacting atan elevated temperature compounds of the formula:

m R -m-n tnXn with phosphates of the formula:

;-M0i (OR')2 in which X represents halogen or' .O fO PS;;M is hy drogen or a metal, preferably an alkali metal or alkaline asthose represented abtove. Although it is not e's'sential, itis'preferred that the above reaction be carried out in the presence of an inert organic solvent. Examples ofgsuitable solvents are aromatic hydrocarbons, such 'as' benzene', toluene xylene, naphthas; aliphatic hydrocarbons,

such as hexane, heptane, octanejhalogenated aliphatic hexyl ether, and thelike.

These catalysts may be incorporated in slow curing one-component and two-component room temperature vulcanizing systems containing organopolysil'oxanes or modified organopolysiloxanes. The one-component system may be represented by the formula:

wherein the R" s, which may be the same or different, are monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals, or cyanoalkyl radicals; Q represents an organopolysiloxane having recurring structural units of the formula:

Illa (-Si 2 or modified onganopolysiloxanes having the formula:

| -Si0 SiO (it l X wherein R, which may be the same or different, represents monovalent hydrocarbon radicals, halogenated monovalent hydrocarbon radicals, or cyanoalkyl radicals; R is a divalent hydrocarbon radical; R is a polymeric organic radical linked to R by a carbon-to-carbon linkage; Z is a radical hydrolyzable by ambient moisture; t is an integer greater than 2; x is an integer of from 0 to 20,000; and y is an integer of from 1 to 500.

'In the above formula, the R s are organic groups selected from the class consisting of alkyl radicals having from I to 18 carbon atoms, such as methyl, ethyl, butyl, hexyl, octyl, decyl, dodecyl, tetradecyl, octadecyl; aryl nadicals, such' as phenyl, diphenyl, naphthyl, and the like; alkaryl radicals, such as tolyl, xylyl, ethylphenyl, and the like; aralkyl radicals, such as benzyl, phenethyl, and the like; haloaryl radicals, such as chlorophenyl, tetrachlorophenyl, difluorophenyl, and the like; alkenyl radicals, such as vinyl, allyl, and the like. R, which may be the same or different, may be the same as R' above; R is a divalent hydrocarbon radical having from 1 to 12 carbon atoms, such as ethylene, trimethylene, tetramethylene, hexamethylene, octamethylene, dodecylmethylene, and the like. R is a polymer or copolymer linked to the organopolysiloxane through a carbon-to-carbon linkage with the divalent hydrocarbon radicals represented by R above. Z represents hydroxyl groups or groups which are hydrolyzable by ambient moisture such as carboxy, OOC-R"" carbonoxy, OR"" aminooxy, -ON(R"") oximo, --ON=C(R") 2 phosphato radicals. R'"', which may be the same or different, represents monovalent hydrocarbon radicals and halogenated monovalent hydrocarbon radicals. Examples of car-boxy radicals are monoacyl radicals of carboxylicacids, such as acetoxy, propionyloxy, valeryloxy, caproyloxy, myristoyloxy, stearoyloxy, and the like. Other hydrolyzable groups are carbonoxy radicals'ha'ving'from v1 to 10 carbon atoms, such as methoxy, butoxy,v octoxy, decoxy,,ph'e- V noxy', 'and' the like. Examples of vaminooxyfradicals are oximo, benzlophenoximo, Z-butanoXirno', isopropylketoxi'mo, chlorocyclohexanoximo, alpha-bromoacetophenoximo, and the like. Examples of suitablephos'phate radtion of these g'raft ipolyiner s.

include combinations of an 'organopolysiloxane (silicone) polymer with an organic polymer, in whichpart or all of the organic polymer is oonnected to the silicone polymer by a carbon-to-carbon linkage. r j

The modified organopolysiloxanes consist of silicone polymers having attached thereto one or more side chains or branches consistingiof a carbon-chain polymer. In preparing these compounds, hydrogen is abstracted from the organosilicone polymerQbya free-radical initiator to form an active site for grafting the organic polymer thereto.

Any silicone polymer may be used in this invention since these polymers areapparently capable of producing some free radicals or active sites under the proper conditions. Thus, the silicone polymer should be one which is capable of producing a substantial and recognizable number of free radicals, and it should be substantially free of any tendency to undergo further polymerization under the conditions employed. Thus, the silicone polymer should be one which is substantially free of any aliphatic unsaturation; however, a low degree of any such unsaturation does not preclude the desired reaction. Preferably, the

silicone polymer has lower alkyl radicals attached to the silicon atoms since these are more amenable to hydrogen abstraction than other. radicals. In addition, it is generally advisable to use silicone polymers which are substantially free of silicon-bonded hydrogen. v, I

Examples of suitable silicone .polymers and copolymers which may be used in the formationof grafted organopolysiloxanes are hydroxyl-terminated siloxane fluids, such as dimethyl fluids, methyl phenyl fluids, copolymers of dimethylsiloxane, and phenyl-, methyl-, or diphenylsiloxane units. If i v In addition, the silicone polymer may be in the form of partially hydrolyzed sila'nes containing residual hydrolyzable or condensable groups, such as silanols, salts of silanols, and partially-condensed polysiloxanes.

Any polymerizableforganic monomer having aliphatic olefinic bonds may be grafted to the silicone polymer. Examples of suitable olefinic,co mpounds are low molecular weight straight-chain hydrocarbons, such asethylene, propylene, butylene; vinyl halides," such as vinyl chloride and vinyl fluoride; vinyl esters of organic acids, such as vinyl acetate; styrene, ring-substituted styrenes, and other 'vinyl aromatics, such as vinylpyridine and vinylnaphthalene; acrylic acid and derivatives of acrylic acid, including the salts, esters, amides, and acrylonitrile; N- vinyl compounds, such as N-vinylcarbazole, N-vinylpyrrolidone, and N-vinylcaprolactam; and vinyl silicon compounds, such as vinyltn'ethoxysilane.

Disubstituted ethylenes of the type .CH CX may be used, including vinylidene fluoride, vinylidene chloride, vinylidene cyanide, methacrylic acid, and compounds derived therefrom, such as the salts, esters, and amides,

as well as methacrolein, methacrylonitrile, and the like.

, .Examplesof disubstituted ethylenes of the type I I CHX= CHX such as iiinylenecarbonate, and various monomers which polymerize best in the presence of other monomers, e.g. maleic'anhydride, esters of maleic and fumaric'acids, stilbene, indene, and cdujrnarone, may be used in the forma- I The monomersm'ay beused singly orfin combinations of two or three or even' mo'rel The properties of the modified product, of course, depend on the nature and identity of themonomer material, as well as on the amounts used relative to the organopolysiloxanes.

The grafting operation is most expeditiously effected by using a free-radical initiator, normally organic peroxides, althou'g'h other free-radical initiators, such as amcompounds, in which both the N atoms of the azo linkage are attached to a tertiary carbon atom and the remaining valences of the tertiary carbon'atom are satisfied by nitrile, carboxylalkyl, cycloalkylene, or alkyl radicals, preferably having from.1 to 18 carbon .atoms. In addition to the above mentioned initiators, ionizing radiation may also be used to bring about the formation of free radicals.

Examples of suitable peroxides which are operative in this invention are hydroperoxides, such as t-butyl hydroperoxide, cumenehydroperoxide, decalin hydroperoxide; dialkyl peroxides, such as di-t-butyland dicumyl peroxide; cyclic peroxides, such as ascaridole and 1,5-dimethylhexane-1,5-peroxide, and peresters, such as t-butyl perbenzoate, t-butyl peroxyisopropylcarbonate, and t-butyl peroctoate; ketone peroxides such as acetone peroxide and cyclohexanone peroxide, are also applicable.

The amount of free-radical initiator employed is not critical, thus any amount capable of producing a perceptible degree of grafting is suitable.- Generally, as little as 0.05 percent of the more active peroxide initiators based on the weight of the monomer is adequate in most cases. However, where it is desirable to increase the reaction rate, then as much as 3 percent or even more of the initiator may be used.

If desired, the unreacted monomers may be separated from the grafted producted by any conventional technique known in the art, such as by distillation, solvent extraction, or selective solvent fractionation.

In the one-component system, hydroxyl-terminated organopolysiloxanes or modified organopolysiloxanes may be reacted with silanes of the formula:

R"TSiZ wherein R, Z and t are the same as those represented above in a ratio of at least 1 mole of the silane per mole of silicon-bonded hydroxyl group at a temperature ranging from about 20 C. to about 100 C. Higher or lower temperatures may be used, if desired, although it is preferred that the reaction be carried out at temperatures below about 200 C.

The organopolysiloxanes having functional groups on the terminal silicon atoms may be cured by merely exposing them to moisture in the atmosphere or in the presence of additional water vapor at room temperature. Upon exposure to moisture, cross-linking of the composition occurs at times varying from a few minutes up to several hours, depending upon the type ofhydrolyzing group and the substituents present on the phosphatostannane catalyst.

In order to obtain a satisfactory cure in the two-component system, the phosphatostannane catalysts are incorporated in a composition comprising a cross-linking agent and an organopolysiloxane, preferably a hydroxyl-terminated organopolysiloxane having the formulae:

. v Ra 7 R B I -S1O HO Si H and H0 -SiO l H t t x+1 x no y wherein R, R, R, x and y are the same as those mentioned above. v These organopolysiloxanes may be cross-linked with polyalkoxysilanes of the formula:

- h K h-z or polyalkoxysiloxanes in which the silicon atoms are linked through SiO-Si bonds, and the remaining valences of the silicon atom are satisfied by R 0 and/or R In the above formula, groups represented by R are monovalent hydrocarbon radicals having less than 8 carbon atoms, while those represented by R are monovalent hydrocarbon radicals or halogenated hydrocarbon radicals of less than 8 carbon atoms, and 2 has a value of from 3 to 4. Examples of monovalent hydrocarbon radicals represented by R are methyl, propyl, butyl, hexyl, octyl, phenyl, vinyl, 'allyl, ethylallyl, butadienyl, and the like. The radicals represented by -R may be the same as the radicals represented by R as well as the corresponding halogenated groups, such as chloromethyl, 2 bromo-4,6-diiodophenyl, 1,2-difiuorovinyl, 3,4-difiuorocyclopentyl, 2- bromocyclopentene-2,3-yl, and 6-chlorohexyl. The polyalkoxysilanes employed herein include monoorganotrihydrocarbonoxysilanes, tetrahydrocarbonoxysilanes, e.g., orthosilicates and partial hydrolyzates of such silanes. The polyalkoxy compounds, e.g., ethyl orthosilicate or partially hydrolyzed ethyl silicate, such as ethyl silicate 40 which consists primarily of decaethyl tetrasilicate, are representative of these compounds. Examples of other operative alkyl silicates are ethyltrimethoxysilane, methylbutoxydiethoxysilane, propyltripropoxysilane, methyltriethoxysilane, ethyltriethoxysilane, ethyl orthosilicate, and butyl orthosilicate. Examples of alkylpolysilicates are ethylpolysilicate, isopropylpolysilicate, butylpolysilicate, dimethyltetraethoxydisiloxane, trimethylpentabutoxydisiloxane, and the like.

The polyalkoxysilanes and polyalkoxysiloxanes employed herein may be used either alone or in combination. They should be used in a proportion of from about 0.5 to about 10 percent, preferably from about 1 to 5 percent by weight based on the weight of the organopolysiloxane. If the total weight of the polyalkoxysilanes or polyalkoxysiloxanes is below about 0.5 percent based on the weight of the organopolysiloxane, very little cross-linking occurs. If, on the other hand, the total weight of the polyalkoxysilanes or polyalkoxysiloxanes is above about 10 percent based on the weight of the organopolysiloxane, the curing time will not be substantially reduced. However, a large excess of cross-linking agent insures complete reaction with all silicon-bonded hydroxy groups and in addition, acts as a scavenger for any moisture which may be present.

The curing of these organopolysiloxane compositions is brought about by mixing the hydroxyl-terminated polysiloxanes with polyalkoxysilane or siloxane cross-linking agents in the presence of the phosphatostannane catalysts of this invention. These catalysts may be dispersed in an inert solvent and then added to the polysiloxane composition, or they may be dispersed on a filler and thereafter milled with the organopolysiloxane. Examples of suitable hydrocarbon solvents are benzene, toluene, xylene, and the like; halogenated hydrocarbons, such as perchloroethylene or chlorobenzene; organic ethers, such as dibutyl ether and the like or fluid hydroxyl-free polysiloxanes. It is preferred that the solvents be of sufiicient volatility to vaporize off at a very low temperature.

The phosphatostannanes used in the curing of these organopolysiloxanes are effective in minimal amounts, e.g., from about 0.05 to about 2 percent, preferably from about 0.1 to about 1 percent by weight based on the weight of the composition. A mixture of two or more of the above phosphatostannane compounds may be used as catalysts in order to provide variable curing times. As mentioned previously, these phosphatostannane catalysts may be added to the organopolysiloxane or, for convenience, they may be first incorporated in a carrier, such as a liquid or comminuted solid, or they may be added to both solid and liquid components. Generally, the carrier is inert but in some cases it may be functional.

The amount of catalyst added to the base composition is determined primarily by the requirements of the particular job, especially the pot life or working time required. In caulking, for example, the working time is more or less conveniently calculated as of the order of from about 1 to 2 hours. Thus, in this instance, the catalyst is added in an amount which Will not result in any substantial stiffening of the silicone composition until after expiration of such period of time. Normally, the composition is tack-free Within 2 to 4 hours following the caulking operation and is substantially cured after about 24 hours and completely phato stannane.

cured after .about ,7 days. ,Tl1ese periods, of course,,vary somewhat with change. in humidity andtemperature conditions. 'Ijhus, a. faster cure results under conditions of high ,temperature andhighhumidity. 1 V

Although-it's not essential, oftentimes it is desirable to incorporate fillers in these compositions in order ,to impart desirable physical properties. Examples of, suitable fillers are fumed silicas, high surface-area-precipitated silicas, silicaaerogels, as well as coarser silicas, such as diatornaceous-earth, crushed quartz, and the like. Other fillers. which may be used are metallic oxides, such as titanium oxide,'ferric oxide, Zinc oxide, and fibrous fillers, such as asbestos, fibrous glass, and the like. Other additives, such as pigments, antioxidants, ultraviolet absorbents, and the like, may be included in these compositions.

Even though the particle size of the filler and additive is not critical, it is preferred that they range from about 0.1 millimicron up to about 2 millimicrons in diameter. Particles of larger diameter may be used; however, they may be more difficult to incorporate in the composition.

The organopolysiloxanes may be compounded in the usual manner for preparing conventional siloxane elastomers; however, where the materials are stored prior to use, it is essential that the phosphatostannane catalysts or cross-linking agents, such as polyalkoxysilane or polyalkoxysiloxane, be stored separately. In other words, the hydroxyl-terminated polysiloxanes, filler, and cross-linking agent may be compounded and the stannane catalyst added just prior to use. In another method, the polysiloxane, filler, and catalyst may be compounded and then the cross-linking agent added just prior to use. If an inert filler is used, it may be added either to the hydroxyl-terminated organopolysiloxane or the cross-linking agent prior to the addition of the catalyst or immediately after the reactants have been combined. The composition will cure spontaneously at room temperature upon mixing the ingredients, i.e., the organopolysiloxane catalyst, cross-linking agent, and filler, if desired.

The phosphatostannane catalysts of this invention will produce a tack-free surface ranging from a few minutes up to several hours, depending upon the type and concentration of catalyst. In addition, mixtures of the catalysts containing various substituents on the tin atom will accelerate the curing time of the entire exposed section. Thus, a complete cure which generally takes from 3 to 7 days without a catalyst may be effected in as little as about 30 minutes with the catalyst described herein when applied in the proper concentration. The use of these phosphatostannane catalysts in oneand two-component systems, such as described above, is as previously noted without precedent in the art.

The catalysts described herein may be used in room temperature vulcanizing compositions to produce variable curing times. These compositions may be used in connection with dental impressions, sealants between adjacent sections of highway, insulation material for electrical components, gaskets, adhesives, and the like.

Various embodiments of this invention are further illustrated in the following examples in which all parts are by weight unlessotherwise'specified;

EXAMPLE 1 To a'reactor containing about 19 parts of dibutyldibutoxystannane and about 50 parts of toluene is added about 7.7 partsv of diethyl hydrogen phosphate in-about 10 parts of toluene. After refluxing the reaction mass for about 3- hours, the reactor is evacuated and the solvent removed by vacuum distillation. The temperature of the reactants is maintained at about 80 C. during the vacuum distillation. A translucent liquid product is obtained which is identified as dibutylbutoxy(diethylphos- EXAMPLE 2 In accordance with the procedure describedin Example 1, 15.5 parts of diethyl hydrogen phosphate in about 10 parts ofi t oluene is added to about .parts of dibutyldibutoxystannane in about 50 parts ofitoluene; A viscous, translucent, brown liquidis obtained which is identifiedas dibutylbis (diethylphosphato-),stannane,-

. EXAMPLE 3 Approximately 295 parts of dibutyldimethoxystannane in about IOOY'parts of be'nzene is' reacted withabout 15.4 parts of diethyl hydrogen phosphate in about 50' parts of benzene at reflux temperaturefor about2.5 hours. The solvent is then removed at about C. at 21 mm. Hg

' for about "2.5 hours. A white opaque, viscous liquid is obtained which is identified as dibutylrnethoxy dicthylphosphato)stanna ne. i Y

EXAMPLE 4 In accordance with the procedure described in Example 1, approximately 49 parts of dioctyldibutoxystannane"in about parts of toluene is reacted with about 15.3 parts of diethyl hydrogen phosphate in about 25 parts of toluene at reflux temperature for"amout 2.5 hours. Volatile ingredients are removed under vacuum yielding a product which is identified as dioctylbutoxy(diethy1- phosphato)stannane. i i

EXAMPLE 5 I Approximately 41.8 parts of diphenyldibutoxystannane in about 1 00 parts of toluene is reacted with about= 15.3 parts of diethyl hydrogen: phosphate in about 25 parts of toluene at reflux temperature for about 2 hours. After removing the solvent/under vacuum distillation, a reaction product is recovered which is identified as diphenylbutoxy(diethylphosphato)stannane. a

' EXAMPLE 6 Approximately 24.8 parts of butyldimethoxychlorostannane in about 100 parts of toluene is reacted with about 21 parts of dibutyl hydrogen phosphate in'about 30 parts of toluene in accordance with'the procedure described in Example 1. The solvent is removed under vacuum distillation and a product is recovered which is identified as butylmethoxy(dibutylphosphato)chlorostannane.

EXAMPLE .7

Approximately 26.9 parts of butyltrimethoxystannane in about 75 parts of toluene is reacted with about 25 parts of dimethyl hydrogen phosphate in about 50 parts of toluene in accordance with the procedure described in Example 1. The solvent is removed under vacuum distillation and a product is recovered which is identified as butylmethoxybis(dimethylphosphato)stannane.

EXAMPLE 8 f Approximately 49.1 parts of dibutyldioctyloxystannane in about .150 parts of :toluene is reacted with about 26.5 parts of dihexyl hydrogen ,phosphate in about 5.0,.parts of toluene in accordance with the procedure described in Example 1. The solvent is removed under vacuum distillation andresidual product is recovered which is identified as dibutyloctyloxy(dihexylphosphato)stannane.

' "EXAMPLE l0 Approximately 41.1 parts of dibutyldibutoxysta' nnane 'in about 100 partsof benzene is reactediwith about 25 parts of diphenyl hydrogen phosphate in'about 50 parts of benzene in accordance with the procedure described in Example 1. The solvent is removed by vacuum distillation and a residual product is recovered which is identified as dibuty-lbutoxy(diphenylphosphato)stannane.

,. .EXAMPLEYI EXAMPLE 17 A reactor containing about 31 parts of the modified hydroxyl-terminated organopolysiloxane prepared in accordance'with the procedure described in Example 16(a) I I an 239 ts r a... th ldiethox'stannane 5 is" i l i 10 mintltcs i 3 Parts 33235 p r t of t l u ene is rea cte d with about 32 3 ethyl slhcate 40,7 13 added Wlth aglt'atlon About part of 1161111 catalyst prepared, in accordancewith Exparts of.'d loctyl' hydrogep phosphate m about. 7 parts of ample 1 is added and the product placed in a mold'and toluene in accordance with the procedure described 111 Ex? cured at room temperature It cured to a tacbfree condi ample 1. The solvent is removed by vacuum distillation 10 tion in about 1 hour 29 i gp L reixovereswmm lsylfientlfied as In a similar experiment, about 10 parts of Cab-O-Sil y et octy P osp ato)s annane" is mixed with the above composition and placed in a mold E EXAMPLE 12 to cure at room temperature. Again, the composition I cured to a tack-free condition in about 1.2 hours.

ApProxlmately Parts of methyldlethmychlomtan- 15 In another experiment, polydimethylsiloxane having a name in-about 7 5 parts of toluene is reacted Wfl about viscosity of about 2000 cs. is substituted for the modified Parts of dleihyl hydrogen Phosphate m about 50 organopolysiloxaneinthe above example.Aproduct cured parts of toluene in accordance with the procedure deto a tackhee condition in about 13 hours scribed in Example 1. The solvent is removed by vacuum dstillaitign and atfi'elsliduel ishrfcovl lelred which is EXAMPLE 1 v t Y I 0s a o c oros ann-ane. 1 ml e as me y 1e yp P About 31 parts of modified organopolysiloxane pre- EXAMPLE 13 pared in accordance with the procedure described in Ex- 1e 16(b) is mixed with about 3 parts of methyltri- Approximately 30.8 parts of diethyl hydrogen phosphate amp in about 50 parts of toluene is reacted with about 30.9 acetoxysllime and about J fi of the UH parts of dibutylethoxymethoxystannaue in about 100 parts Prepared m accoidance t e 'prpcedure descnbed m of toluene in accordance with the procedure described in Etxample The tprodlllct 1S z i fmold Example 1. The solvent is removed by vacuum distillation g 5 t cure to ac fee con mon m and a residual product is recovered which is identified as a g gg g p a polydimethylsiloxane having dlbutylblsmlethylphosphatoktannafle a viscosity of about 2000 cs. is substituted for the modified EXAMPLE l4 organopolysiloxane in the above example. Again, the About 308 parts of diethyl hydrogen phosphate in about product cured to a tack-free condition in about 0.07 hour. 50 parts of toluene is reacted with about 34.5 parts of E MPLE benzyltriethoxystannane in about 100 parts of toluene in XA 19 accordance with the procedure'described in Example 1. ut 31 parts of emodlfifid OTgaIIOPOIYSQOXaIIP P The solvent is removed by vacuum distillation and a residpared 111 accoffiamfe wlthfhe Procedure descrlbed 111 ual product is recovered which is identified as benzylethp 1S mlXfid Wlth about 3 Parts Of methyltfloxybiswiethylphosphato)stannane; acetoximosilane and about 0.01 part of the tin compound 40 prepared in Example 1. The product is placed in a mold EXAMPLE 15 and cured at room temperature. It cured to a tack-free About 30.9 parts of 2-butenyltriethoxystannane in about about 100 parts of toluene is reacted with about 30.8 parts of F a Flmllar experiment, polydllpethylslloxane haYlng diethyl hydrogen phosphate in about 50 parts of toluene a viscosity 0t about 2 000 cs. 18 substituted for the modified in accordance with the procedure described in Example 1. orgfmopolyslloxane the Q P elfample- Product The solvent is removed by vacuum distillation and a residagam cured to a tack'free condltlon 111 about hourual product is recovered which is identified as 2-butenylbis(diethylphosphato)ethoxystannane. EXAMPLE 20 I EXAMPLE 16 In accordance with the procedure described in Example 18, the modified organopolysiloxane prepared in accord- Grafted organopolysiloxanes are prepared by reacting ance with Example 16(b) and methoxytriacetoxysilane olefinic compounds with hydroxyl-terminated polydimethare substituted for methyltriacetoxysilane. The product ylsiloxanes in the presence of a free-radical initiator at a cured at room temperature to a tack-free condition in temperature of from about to 190 C. The unreacted 55 about 0.08 hour. olefinic compounds are removed at an elevated tempera- In a similar experiment, a polydimethylsiloxane having ture by applying a vacuum of 1 mm. Hg or less while com a viscosity of 2000 cs. is substituted for the modified tinuing to agitate for an additional hour. The pertinent organopolysiloxane in the above example. The product datais illustrated in T able I. cured to a tack-free condition in about 0.1 hour.

TABLE I Hydroxylated Free-radical Reaction Olefinie compound fluid initiator I conditions 1Final Viscosity, Temp., Time, viez s i t g Example number Type 1 Parts cp. Parts Type Parts 0. hr. cp.

10a ..{-ffg gf 2 1,000 50 'tBP 0.5 1.5 I 14, 000 10(0 -.{%ff 8 800 40 t-BP 0.5 80 1.7 7,300

Aerylonitn'le- .1. 9. 1 16(0) {Ethylacrylate" 2.0 800 40 t-SP 0.25 a0 2.0 1 20,200

Butyl acrylate 48. 0 16(d) Methacryl 50.0 400 50 t-BP 0.5 80 4.0 15,500 Lauryl methacrylat 70.0 400 30 tBP 0.6 80 5.0 19, 400 1 535553555155 010 304 t-BP 2.0 24.0 3 14,500 16(g) Vinyl Phlnridfl '1: 45.0 s, 700 350 t-BPer 1.8 80 4.0 17,800

No'rE.-t-SP =t-butyl peroxide; t-BPer=t-butyl peroctoate.

H A BL 21 W 3 P s 912 a. mal ed"Bataa t m prepared accordance with the procedure: described in.EX-

ample l6(f}). .islmixed with about 3 gamer 'methyltris( diethylphosphato) silane andaboutQDl part of the;.tin compound prepared in accordance. with the procedure described in Example.1.-The .prd'duct is; placed ina mold and cured at room temperature to a tack-free condition in about 1.8 hours.

In a similar experiment, a polydimethylsiloxane having a viscosity of .ab o1 1 t], 2000 cs is substituted for. the modified organop'olys iloxane 'of the above example. Again, the product cured at room temperature to a tackfree condition in about 2.0 hours.

EXAMPLES 22 THROUGH 42 In accordance with the procedure described in Example 17, organopolysiloxanes are reacted with various crosslinking agents in the presence of the catalysts prepared 1 in Examples 1, 2, and 15 and cured in ambient moisture at room temperature. The results of these experiments are illustrated in Table II.

R is selected from the group consisting of alkyl radicals,

'- ary'l' I radicals, alka'r'yl 1 r'adica1s,"faralky1 radicals; 'alk enyl radicals and'haloaryl' radicals; 'R is selected from" the g oup' consisting of alkylg 'arl'yl a'nd haldalkyl'radicalsf R" is selectedfrom the 'gfroup consisting of alkyl and aryl radicals; m is anjintege'rof'at least 1' and up to "2;;n-is

and m is equal to 2.

TABLE II 7) Cross-linking f; agent OH-polysiloxane Filler Catalyst Cure, Example time; Number Type Parts Ex. No. Parts Type Parts Ex. No. Parts hours 3 16(a) 31 "0o 3 16(a) 31 0.05 3. 00

3 16(a) 3 O. 05 1. '20,, i 3 PMS 0. 20 4. 00 3 16(i) 0.20 0. 50 3 16(f) 0.20 .00: j 3 16(1) 0.20 3.00 '3 16(f) 0.30 a PMS 0'02} 1.60 3 PMS 0.25 3 PMS 0 05 0.12 3 16(0) 0. 20 2.00 3 16(e) 7.00 3 16(6) 0. 20 4. 00 3 PMS 2. 20 3 PMS 0. 20 z 1. 50 I 3 16(g) 7.00 3 16(g) 0.20 :3. 20 3 16(0) 0.20 18.00 3 PMS 0. 20 5. 50 3 PMS 31 12 0.20 )1.

1 Carbon tetrachloride (20 parts).

No'rE.-ES4 "=ethyl silicate 40; DBT DL=dibutyltin dilourate; PMs -polydimethylsiloxane (2 1000 cps); MTAS=methyltriacetoxysilane; MTPS=methyltris(diethylphosphato)silane; MTOS=methyltris(acet- I oximo) silane.

When the above examples are repeated utilizing other cross-linking agents which other phosphatostannane catalysts, elastomeric materials are obtained Which have properties substantially equivalent to those of the specified examples.

Although specific examples have been described herein, other variations and modifications falling within the spirit and scope of the appended claims are to be included therein.

The invention claimed is:

1. A compound having the formula:

gen, 0 and V wherein Y is selected from the group consisting of haloi.252'-"-43l, "437 6. The compound of claini' 1 vvherein Y is halogen and f ifl4 "j v UNITED sTATEsPATENTs- 3,478,088 11/1969 Revukas -260 429.7 9/1962 Hartle zen-429.7

TQBIAS E. LEVOW; Primary Examiner W. F. W. BELLAMY; Assistant Examiner 

